The present invention is directed to a method and apparatus for remote control of electrical or electrically actuated systems, such as for example heating, ventilation and air conditioning (HVAC) systems, lighting systems, security systems, lawn sprinkler systems and the like.
Computerized automation systems can improve control over HVAC systems, and when combined with communicating thermostats, can result in reduced cost, as well as enhanced operational convenience and comfort. Communicating digital thermostats provide the reliability of conventional thermostats, plus the ability to communicate with an automation system. While such digital thermostats control heating and air conditioning on their own, they can also accept temperature set point changes from the computer controller and can send the current temperature and heating and air conditioning operating conditions to the computer controller, for the purpose of implementing a control regime.
Because communicating thermostats install in place of conventional thermostats, they may be used with different brands of HVAC systems. The relays in these thermostats replace the contacts inside a conventional thermostat. The HVAC system operates as it would with conventional thermostats, including special features, but with the added control of the computer system. Software in the computer controller uses information from the thermostats, along with time of day schedules, outside weather conditions and interior conditions to improve management of the HVAC systems. Such energy control systems therefore can include, for example:
Multiple temperature changes throughout the course of a day, with separate schedules, for example, for days of the week and holidays.
Separate temperature schedules for each of the thermostats included in the HVAC system
Preheating and precooling of environmentally controlled spaces during periods of low energy cost, depending on the outside temperature and the actual local interior temperature
Computer enforced limits on the amount by which a temperature can be changed, and for how long; and
Tie-in between the security system and the energy control system.
In automated, centrally controlled systems such as described above, the status of all thermostats can be monitored centrally from a computer controller. Typically, icon displays show the current temperature, as well as heating and cooling set points for each thermostat included within the system, together with its operating mode (off, heat, cool, auto) and other information. Each of the respective thermostats is then separately controllable from the central location.
An important feature of systems such as described above is that, with appropriate communications capacity, the HVAC system can be monitored, and settings changed, over an internal network, via the Internet, or by dialing into the energy controller. Such remote operation can improve service, and save trips to the operating site. Remote access is typically secured by the use of special software, codes and passwords.
Known energy control systems of the type described above have been implemented using either a dedicated processor or a PC as a system control unit. Remote accessibility is then provided only via a proprietary software protocol, or by a slow generic PC communications products, which are commercially available for linking PC""s via the Internet. One communication package which is available for this purpose, for example, is known as pcAnywhere(trademark). FIG. 1, for example, illustrates this type of control system, using a PC for the central control unit. In this embodiment, a PC controller 1 controls a plurality of controlled devices 2 using information supplied by the control devices, as well as by a suite of sensors 3, which provide information concerning local ambient conditions at each of the control devices. The PC controller in this case provides an xe2x80x9call-in-onexe2x80x9d system, which includes not only a system control database, monitoring and control logic and an interface to the control devices 2, but also the hardware and software for graphic user interface. As noted previously, remote access to the system controller PC can be obtained only by a proprietary protocol or a dedicated or dial-up communications line.
FIG. 2 shows a second embodiment of an energy control system according to the prior art, which is similar to the embodiment shown in FIG. 1, except that in place of a PC, a dedicated processor 1a is used.
Each of the foregoing prior art systems suffers from a number of common deficiencies. In particular, and most importantly, communications between a remotely situated PC and the system control PC is extremely slow and unreliable. As a practical matter, such systems can be very inconvenient in use. In addition, the prior art systems described above do not provide a built-in security system which constrains actions that may be taken by a user who has logged into the system via the remotely situated PC. And finally, the controller itself must be either a PC or an equivalent dedicated processor, which is capable of performing all of the functions previously described, including processing for graphic user interface display and processing of input actions taken by a system user; this in turn necessitates the use of equipment having sufficient computing and memory capacity to accommodate such tasks. Accordingly, such systems are costly.
One object of the present invention is to provide an energy control system which is easily and conveniently accessible from a remote location.
Another objection of the present invention is to provide an energy control system in which the functionality of the central control processor is limited, so that low cost computer equipment can be used, without requiring a monitor, keyboard and mouse.
Still another object of the present invention is to provide a control system in which graphic user interface functionality is performed outside the central control unit itself, so that different operating systems may be used for monitoring and control processing on the one hand, and for graphic display processing on the other hand.
Yet another object of the invention is to provide such a control system, which can operate on an embedded processor, without requiring moving storage devices, such as hard drives, floppy or xe2x80x9czipxe2x80x9d disk drives, or CD-ROM drives.
Still another object of the present invention is to provide a remotely accessible energy control system in which input/output interfaces between the control processor and the control devices operate on multiple, small, low-cost processors, separate from a control logic and user interface software.
These and other objects and advantages are achieved by the energy control system according to the present invention, in which an advanced remotely accessible energy control system utilizes a client/server software architecture, and an xe2x80x9copenxe2x80x9d communication protocol that is compatible for communication via a worldwide computer network (such as is commonly referred to as the xe2x80x9cInternetxe2x80x9d); for example, the well known TCP/IP protocol for design-in remote accessibility. In the control system according to the invention, multiple graphic user interface clients can operate on widely available computers incorporating operating systems which are well suited to graphic user interface functions, while the energy control server and the input/output interface components can operate on a separate computer, using other or different operating systems, which are adapted to the processing performed there.
According to the invention, the graphic user interface software is resident on one or more graphic user interface consoles or clients, so that processing for formatting data for display, and processing of input actions taken by a system user are offloaded from the server to the graphic user interface clients. Data describing the format of the display are stored on the server, so a user can move the graphic user interface software to another computer, connect to the server and view the system information, without transporting files describing the format of the display.
Communication between the graphic user interface clients and the server is substantially limited to energy control data and display parameters, such as coordinates at which a device icon is to be displayed. In other words, with the architecture described previously, it is unnecessary for the server to have the capacity to do processing for graphic display of data, or processing of input actions taken by the users, these functions being performed exclusively on the graphic user interface clients. Thus, it is also unnecessary for the server to communicate pixel representations of the display to the client, such as is necessary in the case of generic, third party remote access software, in which all processing is done on the central control unit.
In addition, the energy control system according to the invention also provides a further degree of security that is unavailable in prior art systems, by limiting the range of actions that may be taken by a remote operator via the client PC. That is, in the system according to the invention, communication between the client and server is performed by means of a lexicon of predesignated or xe2x80x9cdesigned inxe2x80x9d messages that limit the actions which the remote operator can take to functions affecting the operations of the controlled devices, excluding modifications to the operation and contents of the server itself. Only administrative and maintenance personnel have access to the operation and contents of the server itself.